| Nowadays, froth flotation is a widely-used method at home and abroad in mineral processing, but this method is not effective in the separation of fine particles and large particles, which results in a lot of metal loss. In order to increase the effictiveness of fine particles and large particles flotation, people in the world have done a lot of research near 100 years. Because of the limitation in froth flotation principle, the problems are yet not completely solved. To do a clear investigation of the microscopic process of the particles interact with bubbles, is the momentous foundation of flotation equipment design and flow-sheet design.On the basis of looking up the data about theory of bubbles interacting with mineral particles in detail, the analysis of mineral particles behaviour in bubble-bed have been made, the conclusion that the free energy varity AG of mineral particles and bubbles pre- and after touch has been drawn, according to the theory, AG is not only relative with touch angle 9, but also with the interface tension of air- liquid, i.e., the increase of hydrophobic nature, the negative AG increases, the touch procedure of mineral particles and bubbles is more easy. In this thesis the possibility of mineral particles touch and abjection with bubbles in water and bubble-bed are analyses. The hydrophobic nature particles are added in bubble-bed directly, the particles can exist in it stability, AG of the system aren't change. So, the possibility of mineral particles touch with bubbles in bubble-bed is greater than in water, and the possibility of mineral particles separate from bubbles in bubble-bed is lower than in water.In the thesis, the settling latest-velocity and the resisting of the hydrophobic mineral particles in water have been studied, and the results are as follows:From the formula, interaction between the surface of hydrophobic fineparticles and water leads a obvious effect to the resisting force when it settle in water, the particles is more finer, the effect is more obvious. And the settling latest-velocity formula of hydrophobic mineral particles is as follows:The free settling latest-velocity of hydrophobic mineral, when it settles in water, is not only decided by the character of mineral and water, but also by the mutual interaction between mineral and water. The settle velocity of cluster mineral particles is studied in thesis, the results show that the logarithm of interference settle velocity keep straight line relation with the logarithm of 1-, that is, with the hydrophobic increase, the interference settle velocity of cluster mineral particle increases.The results of the different size particles settling experiment in water pre- and after hydrophobic treatment have been described in the thesis. From the test results, no matter it is galena, pyrite, quartz or magnetite, the surface hydrophobic is also a factor of the settle velocity of the hydrophobic particles, when the mineral surface is more hydrophobic, the settle velocity is quicker in water. The results have certified that the logarithm of interference settle velocity keep straight line relation with the logarithm of 1-, as well certified the theoretical results that with the hydrophobic is increase, the interference settle velocity of cluster mineral particles increases.The different size particle settling experiment in bubble-bed pre- and after hydrophobic treatment has been described. The kinesic regularity of particle which is different hydrophobic and different sizes, and the effect of size to the settle velocity when particle settle in bubble-bed have been gained. From the test results, the settling of large particle is quicker than the smaller, the hydrophobic also effects the settle velocity, the more hydrophobic of the mineral is, the slower the settle velocity is in the bubble-bed. This is the foundation and reference that mineral particle separate in bubble-bed according hydrophobic nature.The separation experiment of magnetite-pyrite artificial mixed minerals in bubble-bed has been... |
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